Astronomers witness galaxy megamerger

Artist impression of the 14 galaxies detected by ALMA as they appear in the very early, very distant universe. These galaxies are in the process of merging and will eventually form the core of a massive galaxy cluster. Credit: NRAO/AUI/NSF; S. Dagnello

Peering deep into space—an astounding 90 percent of the way across the observable universe—astronomers have witnessed the beginnings of a gargantuan cosmic pileup, the impending collision of 14 young, starbursting galaxies.

This ancient megamerger is destined to evolve into one of the most massive structures in the known universe: a cluster of galaxies, gravitationally bound by dark matter and swimming in a sea of hot, ionized gas.

Using the Atacama Large Millimeter/submillimeter Array (ALMA), an international team of scientists has uncovered a startlingly dense concentration of 14 galaxies that are poised to merge, forming the core of what will eventually become a colossal galaxy cluster.

This tightly bound galactic smashup, known as a protocluster, is located approximately 12.4 billion light-years away, meaning its light started traveling to us when the universe was only 1.4 billion years old, or about a tenth of its present age. Its individual galaxies are forming stars as much as 1,000 times faster than our home galaxy and are crammed inside a region of space only about three times the size of the Milky Way. The resulting galaxy cluster will eventually rival some of the most massive clusters we see in the universe today.

The results are published in the journal Nature.

Zooming in to the galaxies discovered by ALMA that are evolving into a galaxy cluster. The outer field is from data taken by the Hershel Space Observatory. The middle image -- a portion of a much-wider survey by NSF's South Pole Telescope -- uncovered the distant galactic source that was studied by ALMA to reveal the 14 galaxies. Credit: ALMA (ESO/NAOJ/NRAO), T. Miller & S. Chapman et al.; Herschel; South Pole Telescope; (NRAO/AUI/NSF) B. Saxton

"Having caught a massive galaxy cluster in throes of formation is spectacular in and of itself," said Scott Chapman, an astrophysicist at Dalhousie University in Halifax, Canada, who specializes in observational cosmology and studies the origins of structure in the universe and the evolution of galaxies.

"But, the fact that this is happening so early in the history of the universe poses a formidable challenge to our present-day understanding of the way structures form in the universe," he said.

During the first few million years of cosmic history, normal matter and dark matter began to aggregate into larger and larger concentrations, eventually giving rise to galaxy clusters, the largest objects in the known universe. With masses comparable to a million billion suns, clusters may contain as many as a thousand galaxies, vast amounts of dark matter, gargantuan black holes, and X-ray emitting gas that reaches temperatures of over a million degrees.

Current theory and computer models suggest that protoclusters as massive as the one observed by ALMA, however, should have taken much longer to evolve.

Astrophysicists simulated the assembly of a budding cluster of 14 galaxies that was recently discovered by the Atacama Large Millimeter/submillimeter Array. As the simulation progresses, the galaxies merge into one titanic elliptical galaxy surrounded by a halo of galaxies, stars and dust. This configuration resembles that of galaxy clusters seen in the modern universe. Credit: D. Rennehan, A. Babul & B. Moa (University of Victoria); C. Hayward (Flatiron Institute); S. Chapman (Dalhousie University/University of Victoria/NRC Herzberg); P. Hopkins (Caltech)"How this assembly of galaxies got so big so fast is a bit of a mystery, it wasn't built up gradually over billions of years, as astronomers might expect," said Tim Miller, a doctoral candidate at Yale University and coauthor on the paper.

"This discovery provides an incredible opportunity to study how galaxy clusters and their massive galaxies came together in these extreme environments."

This particular galactic protocluster, designated SPT2349-56, was first observed as a faint smudge of millimeter-wavelength light in 2010 with the National Science Foundation's South Pole Telescope. Follow-up observations with the Atacama Pathfinder Experiment (APEX) telescope helped confirm that it was in fact an extremely distant galactic source and worthy of follow-up observations with ALMA. ALMA's superior resolution and sensitivity allowed astronomers to distinguish no fewer than 14 individual objects in a shockingly small region of space, confirming the object was the archetypical example of a protocluster in a very early stage of development.

This cluster's extreme distance and clearly defined components offer astronomers an unprecedented opportunity to study some of the first steps of cluster formation less than 1.5 billion years after the Big Bang. By using the ALMA data as the starting conditions for sophisticated computer simulations, the researchers were able to demonstrate how this current collection of galaxies will likely grow and evolve over billions of years.

"ALMA gave us, for the first time, a clear starting point to predict the evolution of a galaxy cluster. Over time, the 14 galaxies we observed will stop forming stars and will collide and coalesce into a single gigantic galaxy," said Chapman.

This research is presented in a paper titled "A massive core for a cluster of galaxies at a redshift of 4.3," by T.B. Miller, et al., which appears in the journal Nature.

This research was presented in two papers, "The Formation of a Massive Galaxy Cluster Core at z = 4.3", by T. Miller et al., to appear in the journal Nature, and "An Extreme Proto-cluster of Luminous Dusty Starbursts in the Early Universe", by I. Oteo et al., which appeared in the Astrophysical Journal.

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

That 'artists impression' looks impossible. Wouldn't a bunch of galaxies like that exert tidal forces on each other such that they'd be well distorted by the time they were that close? That just looks like a bunch of galaxies were photoshopped together.

Well obviously. When you lookout into deep space you are looking at the past. In fact everything you see is the past. You see your computer screen as it was one billionth of a second in the past. You see the Moon as it was one second into the past, the Sun 8 minutes into the past. When you spot the Andromeda fuzzball in the night sky you're seeing it as it was 2.5 million years ago. For all we know Betelgeuse could very well not even be a star any more, it could have gone supernova a hundred years ago.

I suspect from watching it, that the animation did not take into account expansion of the universe. An additional billion years 1.4 billion years after the big bang should have some expansion effects. Oh, and the galaxies could be clustered by chance given our viewing angle. Also the animation starts with the galaxies at rest. If they are instead moving at significant speeds with respect to each other, the fate of the galaxies may be a cluster of separate galaxies. Just some food for thought that shouldn't diminish finding the cluster. It may be that the Square kilometer array will be able to assign better current velocities to the galaxies.

Measuring the universe with galactic proto cluster'sAt year zero, this galactic proto cluster formed at 1.4 billion years, assuming are Milkyway group is moving at the same speed of 600km/s the distance between the two remains constant at 12.4 billion light-years. This gives an idea of scale, because when the universe was 1.4 billion years old the Milkyway cluster was 12.4 billion light-years away from this galactic proto cluster, which begs the question how big was the universe at 1.4billion years old.

time is poorly understood. but there exists a universality of perception of time and time runs more rapidly in higher gravity and vice versa, which is exactly the opposite to what is postulated by GR. So if you were there you will perceive passage of one hour exactly as you perceive passage of one hour on earth. So it would be wrong to say ' very early after the big bang 'sigh when will science catch up which is sadly bogged down because of GR dogma

when will science catch up which is sadly bogged down because of GR dogma

Oh great. Just what we need - another anti-Einstein crank. Guess what, woo boy? GR is one of the most tested and attested theories ever. It has passed every test it has been set. Including showing that time runs more slowly in lower gravitational potential. You could test it yourself - just like these people did:http://www.leapse...eat2005/

Bloody place is infested with #physicscranks! Go write it up, and save the rest of us from having to listen to your drivel on here.

when will science catch up which is sadly bogged down because of GR dogma

Oh great. Just what we need - another anti-Einstein crank. Guess what, woo boy? GR is one of the most tested and attested theories ever. It has passed every test it has been set. Including showing that time runs more slowly in lower gravitational potential. You could test it yourself - just like these people did:http://www.leapse...eat2005/

Bloody place is infested with #physicscranks! Go write it up, and save the rest of us from having to listen to your drivel on here.

Lol a pendulum slows down on the equator as compared to on the poles. So what does that tell you about where time runs slowly, cranky boy?

when will science catch up which is sadly bogged down because of GR dogma

Oh great. Just what we need - another anti-Einstein crank. Guess what, woo boy? GR is one of the most tested and attested theories ever. It has passed every test it has been set. Including showing that time runs more slowly in lower gravitational potential. You could test it yourself - just like these people did:http://www.leapse...eat2005/

Bloody place is infested with #physicscranks! Go write it up, and save the rest of us from having to listen to your drivel on here.

Lol a pendulum slows down on the equator as compared to on the poles. So what does that tell you about where time runs slowly, cranky boy?

Gravity is the force of oscillationGravity effects the transition period of atomic clocks which effects the oscillation period which is why atomic clocks make accurate Gravimeters. Gravity is simply a physical property exerting a force, the pendulum slows down on the equator as compared to on the poles comparison is exactly the same as the pendulum on the moon, placing atomic clocks on the moon are operating under the same gravitational force as pendulums clocks oscillating under gravity on the moon. Time is not gravity and gravity is not time, the comparison with the transition period of atomic clocks demonstrates gravities purely physical properties. Gravity is exerting a force on the transitional electrons effecting the period between transitions.

when will science catch up which is sadly bogged down because of GR dogma

Oh great. Just what we need - another anti-Einstein crank. Guess what, woo boy? GR is one of the most tested and attested theories ever. It has passed every test it has been set. Including showing that time runs more slowly in lower gravitational potential. You could test it yourself - just like these people did:http://www.leapse...eat2005/

Bloody place is infested with #physicscranks! Go write it up, and save the rest of us from having to listen to your drivel on here.

Lol a pendulum slows down on the equator as compared to on the poles. So what does that tell you about where time runs slowly, cranky boy?

Electron transition frequency in the microwave, optical, or ultraviolet Since the beginning of development in the 1950s, atomic clocks have been based on the hyperfine transitions in hydrogen-1, caesium-133, and rubidium-87Atomic electron transition is a change of an electron from one energy level to another within an atom as the electron jumps from one energy level to another in nanoseconds The Frequency of atomic clocks is altered by Gravity, Magnetism, Electrical Fields, Force, Motion, Temperature and other phenomena.

Age dependant Electron transition frequency in the electrons 66billion year Yotta life span

The best measurement yet of the lifetime of the electron suggests that a particle present today will probably still be around in 66,000 Yotta years 6.6 × 10+28 years, which is about five-quintillion times the current age of the universe. That is the conclusion of physicists working on the Borexino experiment in Italy, who have been searching for evidence that the electron decays to a photon and a neutrino; a process that would violate the conservation of electrical charge and point towards undiscovered physics beyond the Standard Model https://physicswo...tayears/

Age dependant Electron transition frequency in the electrons 66billion year Yotta life span

The best measurement yet of the lifetime of the electron suggests that a particle present today will probably still be around in 66,000 Yotta years 6.6 × 10+28 years, which is about five-quintillion times the current age of the universe. That is the conclusion of physicists working on the Borexino experiment in Italy, who have been searching for evidence that the electron decays to a photon and a neutrino; a process that would violate the conservation of electrical charge and point towards undiscovered physics beyond the Standard Model https://physicswo...tayears/

Electron transition frequency in the microwave, optical, or ultraviolet Since the beginning of development in the 1950s, atomic clocks have been based on the hyperfine transitions in hydrogen-1, caesium-133, and rubidium-87Atomic electron transition is a change of an electron from one energy level to another within an atom as the electron jumps from one energy level to another in nanoseconds The Frequency of atomic clocks is altered by Gravity, Magnetism, Electrical Fields, Force, Motion, Temperature and other phenomena.

Well the atomic clocks digital readout essentially indicates a count down value of the source local oscillator frequency

Electron transition frequency in the microwave, optical, or ultraviolet Since the beginning of development in the 1950s, atomic clocks have been based on the hyperfine transitions in hydrogen-1, caesium-133, and rubidium-87Atomic electron transition is a change of an electron from one energy level to another within an atom as the electron jumps from one energy level to another in nanoseconds The Frequency of atomic clocks is altered by Gravity, Magnetism, Electrical Fields, Force, Motion, Temperature and other phenomena.

Well the atomic clocks digital readout essentially indicates a count down value of the source local oscillator frequency

Got in one savvys84, an atomic clock digital readout is simply counting the number of oscillations; time has nothing to do with it. It is not part of the equation!

when will science catch up which is sadly bogged down because of GR dogma

jonesdave > Oh great. Just what we need - another anti-Einstein crank. Guess what, woo boy? GR is one of the most tested and attested theories ever. It has passed every test it has been set. Including showing that time runs more slowly in lower gravitational potential. place is infested with #physicscranks! Go write it up, and save the rest of us from having to listen to your drivel on here.

jonesdave:- An atomic clock digital readout is simply counting the number of oscillations; Time It is not part of the equation it is simply the force of gravity on the transitional electron which is changing the number of transitions compared to a standard gravitational field. GR has arrived when it readily accepts a readout is simply counting the number of oscillations having nothing to do with time because we're dealing with physical realities.

Electron transition frequency in the microwave, optical, or ultraviolet Since the beginning of development in the 1950s, atomic clocks have been based on the hyperfine transitions in hydrogen-1, caesium-133, and rubidium-87Atomic electron transition is a change of an electron from one energy level to another within an atom as the electron jumps from one energy level to another in nanoseconds The Frequency of atomic clocks is altered by Gravity, Magnetism, Electrical Fields, Force, Motion, Temperature and othhenomena.

Well the atomic clocks digital readout essentially indicates a count down value of the source local oscillator frequency

Got in one savvys84, an atomic clock digital readout is simply counting the number of oscillations; time has nothing to do with it

The watt balance can only be inaccurate and its relation to counting oscillations

savvys84> The atomic clock gives a read out of time. Duh

Another anomaly is the Watt balance depends on the speed of light which is 299792458, if you have noticed the last digit is a whole number where the accuracy of the Watt balance is to 10 or more decimal places and as you must be aware savvys84 the speed of light is not exactly 299792458, but to decimal places e.g. 299792457.99997764... or 299792459.050543.... I think you can jist of what I'm pointing out, the Watt balance can only be inaccurate.133Caesium equals 9,192,631,770Hz where the speed of light moves 29979248metresThe exact amount of time of measuring the speed of light should quoted to its decimal places, and if it is different next month it should be updated, this has knock on effect on atomic clocks, their inaccurate to lights inaccuracies!

The watt balance can only be inaccurate and its relation to counting oscillations

savvys84> The atomic clock gives a read out of time. Duh

133Caesium equals 9,192,631,770Hz where the speed of light moves 29979248metresThe exact amount of time of measuring the speed of light should quoted to its decimal places, and if it is different next month it should be updated, this has knock on effect on atomic clocks, their inaccurate to lights inaccuracies!

I am getting the gist.Tho physical realities are very dependent on time. Look above the conversation between me and jonesdave

In physics it is common practise to obtain measurements by the indirect approach.The Gravitational constant cannot be a whole number constant, but decimal places which it is to decimal places, 6.67408x10-11 which is growing in decimal places with refinement.Lights velocity constant cannot be a whole number constant but to decimal places, proof of this is when it is expressed imperially as feet; feet and inches only convert through an infinite series of decimal places so the speed of light expressed imperially is to decimal places which is growing in decimal places with refinement.It is only possible to measure the flow of time by two constants of an infinite number of decimal places where gravity influences the flow of light in its motion through the vacuum of space which makes the velocity of light an indefinite varying constant depending on the strength of gravity!

In physics it is common practise to obtain measurements by the indirect approach.The Gravitational constant cannot be a whole number constant, but decimal places which it is to decimal places, 6.67408x10-11 which is growing in decimal places with refinement.Lights velocity constant cannot be a whole number constant but to decimal places, proof of this is when it is expressed imperially as feet; feet and inches only convert through an infinite series of decimal places so the speed of light expressed imperially is to decimal places which is growing in decimal places with refinement.

Heck you are on an awful tangent. Now does the atomic clock show the time or not?

savvys84> Heck you are on an awful tangent. Now does the atomic clock show the time or not?

For the privileged few savvys84, a view on how gravity effects are measurement of time using the oscillatory nature of the electromagnetic nature of light under the influence of gravity - I believe it was your honourable self who raised the fact the oscillatory nature of a pendulum in a gravitational field is not an indication of the passage of time!

You cannot measure time using oscillations that are effected by gravity, the ancient seafaring marinas found this out, which is why an accurate chronometer was constructed which gave the same time where ever sailors were on the high seas!.

E-mail the story

Astronomers witness galaxy megamerger

Note

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose.
The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Your message

Newsletter sign up

Get weekly and/or daily updates delivered to your inbox.
You can unsubscribe at any time and we'll never share your details to third parties.

Your Privacy

This site uses cookies to assist with navigation, analyse your use of our services, and provide content from third parties.
By using our site, you acknowledge that you have read and understand our Privacy Policy
and Terms of Use.